Device for throwing or twisting threads, fibres and similar products



Aug. 11, 1959 M. FLEURET 2,898,728

DEVICE FOR THROWING OR TWISTING THREADS, FIBRES AND SIMILAR PRODUCTSFiled Jan. 28, 1958 2 Sheets-Sheet 1 Aug. 11, 1959 FLEURET DEVICE FORTHROWING OR TWISTING THREADS, FIBRES AND SIMILAR PRODUCTS 2 Sheets-Sheet2 Filed Jan. 28, 1958 United States Patent DEVICE FOR THROWING ORTWISTING THREADS, FIBRES AND PROD- UCTS Application January 28, 1958,Serial No. 711,616' Claims priority, application France March 21, 1957 5Claims. (Cl. 57-5833) When a double-twist hollow spindle is used forthrowing or twisting threads, fibres or like flexible elongated members(hereinafter designated thread), it is necessary to impart acertaindegl'ee of tension to the thread between the point at which itleaves a supply bobbin placed on the hollow spindle and the point'atwhich, on leaving the hollow spindle, it forms a balloon, on its upwardjourney as far as a thread guide placed above the supply bobbin. Thistension should have a predetermined value whichdepends, inter alia, onthe nature and on the count or number of the thread, and also on thespeed of rotation of the hollow spindle. It should be sufliciently lowto prevent damage to the thread but sufiiciently high' to stabilize theballoon, i.e. to prevent the diameter thereof fromincreasing beyond acertain limit, due to the action of centrifugal force.

Many devices have already been proposed with a view to solving thisproblem, some of said devices acting by friction on the thread, forexample by nipping the thread between a movable ball and the internalwall. of the hollow spindle, while others consist of a braked element towhich there is imparted a. rotatory movement by the thread unwindingfrom the supply bobbin.

It is an object of the present invention to provide a device for use intwisting or throwing machines using a hollow spindle through which thethread is removed from a supply bobbin.

It is a further object of the present invention to provide such a devicewhich will make it possible to regulate the tension applied to thethread in twisting machines using a hollow spindle;

It is a further object of the present invention to provide such a devicewhich may be used in conjunction with an inlet section detachable fromthe hollow spindle.

Further objects of the present invention will become apparenthereinafter.

The present invention provides a device comprising a thread guide incombination with a double-twist machine of known type, the verticalhollow spindle of which is surmounted by a coaxial inlet element, saidthread guide bearing on a surface of the inlet element, which surface ispositioned in the path followed by the thread between the supply bobbinand the hollow spindle; it should be noted that the coaxial inletelement may be formed by the support for the bobbin supplying thread tothe double-twist machine or the inlet element may be a piece separatefrom the bobbin support, said separate piece being removable ornon-removable from the doubletwist machine. As a result of the manner inwhich the thread guide is arranged, the thread unwound from the supplybobbin has to sweep constantly over said bearing surface before enteringthe hollow spindle.

The present invention also provides a thread guide for use in twistingmachines provided with a hollow spindle through which threads, fibresand like flexible elongated members from a supply bobbin may be drawn,and an inlet element for said spindle, characterized in that the guideis adapted to bear on a surface of the inire let element which surfaceis also part of the path followed by thread on its way to the interiorof the hollow spindle.

One particularly simple embodiment of the invention consists in givingthe thread guide the shape of a letter T having asymmetrical arms. Thestem of the T engages inside the inlet element and one of the arms ofthe thread guide bears on a surface of the said inlet element. This armmay be loaded to a greater or lesser degree by means of weights, so asto regulate the pressure which it exerts on the bearing surface andconsequently also the tension exerted on the thread during the twistingoperation. The other arm carries near its end one or more eyelets orother openings, the position of which is such that the thread passingthrough them is compelled to constantly sweep over the bearing surface.

If the inlet element surmounting the hollow spindle is removable fromthe twisting machine with which it is associated, it will be possible tomanipulate it more easily if the thread guide is fast with the saidelement. This may be very easily provided, in accordance with a specialembodiment of the invention, by the portion of the thread guide whichhas passed through the said element being cranked substantially in theplane determined by the arms of the T and the vertical stem thereof andopposite the arm thereof which carries the eyelet or eyelets or otheropenings. It is extremely surprising to find that the thread does notwind round the said stem when it is cranked as indicated hereinabove,whereas this inconvenience does result and causes breakage when the stemis cranked in a different manner. In order that the thread guide may beseparated from the inlet element when desired, the cranked stem and/orthe inlet element may consist of a plurality of elements which have beenassembled by any known means, for example by screwing.

The device according to the invention is particularly simple and enablesthe tension exactly required to be exerted on the thread, whilst givingthe necessary value to the weight regulating the pressure of the threadguide on the bearing surface; furthermore, the saidtension remainsremarkably constant during the throwing or twisting operation.

Two embodiments of the device in accordance with the present inventionare illustrated in the accompanying diagrammatic drawings, in which:

Figure l'is a cross section through a front elevation of a twistingmachine in which the support carrying the supply bobbin also forms anirremovable inlet element, and

Figure 2 is a cross section through a front elevation of a twistingmachine having a removable inlet element.

In the embodiment illustrated in Figure 1 a doubletwist machine of knowntype is shown comprising a rotatable hollow spindle 21 (adapted to bedriven by means which are not shown) and a fixed coaxial support 2carrying a thread supply bobbin 3 and provided with a channel 4 throughwhich the thread enters the hollow spindle.

A T-shaped thread guide is provided having a stem 5 which penetratesinto the channel 4, an arm 6 provided near its end with eyelets 7, andan arm 8 carrying a weight 9. The arm 3 of the said thread guide bearson a ring-shaped surface Id of the support 2.

In operation, thread 11 is unwound from the bobbin 3 and passes throughthe eyelets 7 before entering the channel 4 and then the hollow spindle1, thus imparting a rotatory movement to the thread guide.

The respective positions of the eyelets 7 and of the bearing surface itare such that the thread constantly sweeps over the said surface duringthe use of the device for effecting a twisting operation.

In the embodiment illustrated in. Figure 2 a doubletwist machine ofknown type is shown comprising a rotatable hollow spindle 20 (adapted tobe driven by means which are not shown), a fixed support. 21 carrying athread supply bobbin 22 and a removable inlet element 23 provided with apassage 24, the axis of which coincides with that of the hollow spindle20.

A T-shaped thread guide is provided having a stem 25 penetrating intothe passage 24, and arm 26 provided with eyelets 27 near its end, and anarm 28 carrying a weight 29. The stem 25 is cranked at 36) in the planedetermined by the arms 26 and 28 and the stem 25, but in the directionopposite to the arm 26. The thread guide and the inlet element are thuslocked into one another; their manipulation, for example for the purposeof placing the bobbin in position, is facilitated, since there is nolonger any risk that the thread guide may slide out of the inletelement.

The arm 28 of the thread guide bears on an annular bearing surface 31 onthe inlet element 23.

As in the first embodiment the thread 32 constantly sweeps over thesurface 31 during the throwing or twisting operation.

The invention has beendescribed with reference to double-twisting orthrowing, i.e. with regard to the case wherein two turns of twist areimparted to a thread, for one revolution of the hollow spindle. Thisapplication is of some considerable commercial importance, but theinvention is not limited thereto and may be used in every case whereinuse is made of a vertical hollow spindle, whether a single turn of twistis imparted to the thread for one revolution of the hollow spindle, or,on the other hand, more than two turns of twist are imparted for eachrevolution of the hollow spindle.

Although the present invention has been described with particularreference to specific details, it is not intended that such detailsshall be regarded as limitations upon the scope of the invention exceptinsofar as included in the accompanying claims.

What I claim and desire to secure by Letters Patent 1. A device forthrowing and twisting threads, fibres and like flexible elongatedmembers comprising, in combination with a twisting machine having arotatable hollow spindle, a channeled coaxial inlet element disposedthereon and provided at its upper end with a ring-shaped surface, and athread supply bobbin disposed around said inlet element, a thread guidehaving a portion thereof bearing on the ring-shaped surface of the inletelement and a portion provided with at least one eyelet situated belowthe level of the upper end of the inlet element,

so that thread passing from the supply bobbin into thehollow spindletravels over the ring-shaped surface in contact therewith.

2. A device according to claim 1, in which the thread guide approximatesthe shape of a letter T having a stem and asymmetrical arms, the stemextending downwardly inside the inlet element, one of the arms of the Tbearing on the said surface of the inlet element, a weight loading saidarm to regulate pressure exerted by the arm on the said surface, and theother arm of the T being provided with at least one opening for thepassage therethrough of the said thread.

3. A device according to claim 2, in which the said stern of the T iscranked substantially in the plane determined by the said arms of the Tand the said stern thereof in a direction opposite to the arm providedwith the opening.

4. A thread guide for a twisting machine having a hollow spindle throughwhich thread may be drawn, a thread supply bobbin for said spindle andan inlet element extending through said bobbin and provided at its upperend with a bearing surface, said thread guide being in the shape of aletter T having a stern and asymmetrical arms, the stem of the Tengaging inside the inlet element, one of the arms bearing on the saidsurface of the inlet element, a weight loading said arm to regulate thepressure exerted thereby on the bearing surface and the other arm of theT being provided with at least one opening for the passage therethroughof the said thread, said opening being situated below the level of theupper end of the inlet element.

5. A thread guide according to claim 4, in which the said stem of the Tis cranked substantially in the plane determined by the said arms of theT and the said stern thereof in a direction opposite to the arm providedwith the opening.

References Cited in the file of this patent UNITED STATES PATENTS1,432,861 Hubbard Oct. 24, 1922 2,499,726 Cotterill Mar. 7, 1950 FOREIGNPATENTS 292,752. Italy Jan. 30, 1932 594,232 France June 13, 1925

